RNP AR
Im a bit lost in this subject as i've flown a VOR CDI or enroute GPS FMS for most of my career, pre-airbus.
i need help with the following
what is RNP AR? (i know what it stands for including RNP SAAAR)
how does flying ILS, VOR or LOC approach raw data, fit here?
what is a GPS app?
a managed LOC or VOR app?
an RNAV (RNP) app?
an RNAV (GNSS) app?
i'd like to understand how this all fits together
hope the questions are clear, ill try to refine as the comments come
thank you!